Light copying apparatus



(No Model.)

H. SACK.

LIGHT COPYING APPARATUS.

Patented Aug. 25, 1885.

q PETERS Photo-Lithographer, Washinglon. D. c.

UNITED STATES PATENT ()FFICE.

HUGO SACK, OF PLAGW ITZ-LEIPSIO, GERMANY.

ILIGHT COPYING APPARATUS.

QPECIPICATION forming part of Letters Patent No. 324,960, dated August 25, 1885.

Application filed December 20, [$84. (No model.)

To all whom it may concern:

Be it known that I, HUGO SACK, a citizen of Germany, residing at Plagwitz Leipsic, in the German Empire, have invented anew and useful Improvement in Light Copying Apparatus, of which the following is a specification.

In light or sun copying apparatus as at present generally arranged the paper upon which the drawing is made, and which is to be copied, and the copying-paper (sensitive paper) are placed below a plate of glass and the latter pressed tight against the papers. By this arrangement the glass plate must either be very thick, strong, and perfectly even, or there is great danger of springing or breaking the glass plate.

My improvement consists in an arrangement whereby the copying paper and the paper containing the drawing are forced against the face of the glass plate by the atmospheric pressure, by which arrangement not only the glass plate may be made considerably lighter or thinner, and the same need not be perfectly smooth or straight, and instead of the ltte of glass some transparent membrane may be substituted.

In the accompanying drawings, Figure I represents a longitudinal section of my improved apparatus. Fig. II is asection of part of the same with a suction arrangement attached.

Similar letters represent similar parts.

A is the usual plate of glass. B represents the sheet of paper or other material upon which the drawing or picture is made which is to be printed. 0 represents the sensitive paper upon which the drawing is to be copied or printed. D is a perforated sheet or any suitable material through which the air can pass. E is an air-tighttlexible material, such as india-rubber cloth. To this material or cloth (preferably in the center) an air-tight tube, 1*, is attached.

The different parts being arranged upon each other in the order above enumerated and shown in the drawings, the atmospheric air is drawn ofl" from between the plate of glass A and the airtight material E by the application and action of the mouth, or by the ar -scribing witnesses.

rangement of any suitable suction apparatus, G, at the end of the pipe F. When the air has been withdrawn, the pipe F must be closed by a suitable cock or other arrangement, (not shown in the drawings,) when the appara tus is ready to be exposed to the light in the usual manner. The air having been with drawn from between the plate of glass A and the air-tight material E,the atmospheric press ure against the outside of the material E will insure the perfect tight laying of the different materials against the surface of the plate of glass or other transparent membrane, even if the surface of the same should not be perfeet] y smooth or straight, and will prevent any danger of breaking the plate of glass, even if the same should be very thin.

The air-tight material E may be provided with an air-cushion, J, around its circumfen ence, resting outside of the sheet of drawing, B, the paper 0, and the sheet D upon the plate of glass, A, and may be held or pressed upon the glass by a suitable frame to stop the admission of air around the outside, and thus assist the withdrawing or exhaustion of the air; or this air-cushion J may be attached to a suitable frame and pressed upon the outer circumference of the material E.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In combination with the glass plate A, paper B, containing the drawing to be copied, and the sensitive or copying paper 0, the per forated material D, and the air-tight material E, provided with a pipe, F, and suitable suction apparatus, substantially as and for the purpose set forth.

2. The combination, with the air-tight material E and the glass plate A, of a light copying apparatus, and the air-cushion .1, around the outer surface of the air-tight material, in the manner and for the purpose described.

I11 testimony whereof I have signed my name to this specification in the presence of two sub- HUGO SACK.

\Vitnesses:

(J. LEONI-IARD'L, \V. RUPP. 

